loki update to 6.6.4-bb.6

Package Merge Request

Package Changes

https://repo1.dso.mil/big-bang/product/packages/loki/-/blob/6.6.4-bb.6/CHANGELOG.md

Package MR

big-bang/product/packages/loki!259 (merged)

For Issue

Closes big-bang/product/packages/loki#191 (closed)

Upgrade Notices

Loki now has the option to expose it's API via a virtual service. As called out in Loki documentation here, access to this API is NOT secured. If secure access is required, Loki's API MUST be secured using a reverse proxy of your choosing.

Big Bang does NOT enable the API service by default.

Customers should be aware of the security implications of setting loki.values.istio.loki.enabled to true.